Twins???

Oh gosh, this has been a little bit of a stressful week so far. I went into the midwife yesterday for a regular check-up. The last time I went in Ann (the midwife) couldn't find the baby's heartbeat but wasn't worried about it and this week when she couldn't find it yet again she figured she should do an ultra sound but of course its a really old machine. After putting the goop on my tummy she says, "It's twins, just kidding" then a few seconds later she says "Oh my @#^*, It is twins". She saw two heartbeats for a bit and then couldn't find the second heartbeat. She isn't positive but there is a possibility that I am expecting twins. They also were thinking that I was fourteen weeks along and I am really only ten. This pregnancy I am sick when I never have been before, I am always really tired, I am already showing, I think these could be signs that it is twins, we'll see I guess. I find out for sure next week but it has been driving me crazy not knowing. I wasn't going to tell anyone until we found out for sure but now I cant stop thinking about it and the implications it will have on me and our family. Jeff and I will be married for just barely three years and have four kids and they will all be 2 1/2 and under. Life will really change if it's twins, having another baby will be change enough but two?